HDoom [Techdemo 11] By HDoomguy

Cheats can be used by typing them during gameplay. If you are playing on the highest difficulty, all cheats are disabled.

iddqd — Invulnerability (God Mode)
idkfa — Full health, ammo, weapons, armor and keys
idfa — Full health, ammo, weapons, and armor
idclip — Noclip
iddt — Reveals information while in automap mode, shows more information if used for a second time

Summoning Enemies:
You can summon different enemies by entering summon and their name in the console. Ex: summon archvile

archvile, baronofhell, hellknight, demon, spectre, chaingunguy, doomimp, lostsoul, shotgunguy, and zombieman